1. Field of the Invention
The present invention relates to refrigerating systems for refrigerators, and more particularly, to a control method at the time of initial operation of a refrigerating system.
2. Discussion of the Related Art
In general, the refrigerator cools a space thereof for fresh storage of food therein for a time period while refrigerant (working fluid) repeats a refrigerating cycle of compression-condensing-expansion-evaporation.
Of the refrigerators, a direct cooling type refrigerator is provided with separate evaporators for a freezing chamber and a refrigerating chamber respectively. The direct cooling type refrigerator will be described in detail with reference to FIG. 1.
The refrigerating system of the direct cooling type refrigerator is provided with a compressor 11, a condenser 12, an expansion valve 13, a freezing chamber evaporator 14, and a refrigerating chamber evaporator 15. Various units of the refrigerating system are connected with refrigerant pipes 16.
The compressor 11 compresses low temperature/low pressure refrigerant gas to a high temperature/high pressure refrigerant gas. The condenser 12 receives and compresses refrigerant from the compressor 11. The expansion valve 13 receives refrigerant from the condenser 12 and drops a pressure of the refrigerant. The freezing chamber evaporator 14 and the refrigerating evaporator 15 evaporate the refrigerant from the expansion valve 13 in a low pressure state, to absorb heat from air in the vicinity of the evaporators 14, and 15. Air cooled down by the evaporators 14, and 15 is supplied to the freezing chamber and the refrigerating chamber for fresh storage of food. Above cycle is repeated continuously while the refrigerator is operated.
However, the substantially long refrigerant pipes 16 of the refrigerating system of the related art direct cooling type refrigerator due to the two evaporators 14, and 15 requires large quantity of refrigerant filled in the refrigerating system. Therefore, even though a high torque is not required for the compressor 11 once operation of the refrigerating system is stabilized after the refrigerating system is operated for a certain time period, a high torque, with consequential high voltage, is required when the refrigerating system starts operation, i.e., the compressor 11 starts operation. That is, the related art refrigerating system uses a compressor of which torque is high unnecessarily due to above initial operation problem.